How much you earn mostly depends on your demographic, the types of offers you complete, and the time and effort you're willing to put into it.

In my experience so far (being in the US), it's trivial to earn $1-5 USD a day with a little bit of time spent doing just the free offers/daily surveys! If you're motivated and have the time I've seen people earning $25-50 USD a day just doing the recurring tasks (when the right ones are available)! There are lots of ways to earn, and they're always adding more, so just play around and figure out what you like to do that works for you.

This may not seem like much, but it adds up pretty quick. This is not even counting referral bonuses or winnings from games! Plus with the daily surveys, you have the added benefit that your input actually helps improve and create products and services!